1.0.0.3 false CONSOLIDATED BALANCE SHEETS (USD $) In Thousands false 1 $ false false Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 USDPerShare Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 false 2 $ false false Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 USDPerShare Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 4 Current assets: 2 us-gaap_AssetsCurrentAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 5 Cash and cash equivalents 3 us-gaap_CashAndCashEquivalentsAtCarryingValue us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 true true 2544000 2544 false false 2 true true 1213000 1213 false false No definition available. No authoritative reference available. false 6 Restricted cash 3 us-gaap_RestrictedCashAndCashEquivalentsAtCarryingValue us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 593000 593 false false 2 false true 502000 502 false false No definition available. No authoritative reference available. false 7 Short-term investments 3 us-gaap_ShortTermInvestments us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false false 0 0 false false 2 false true 2502000 2502 false false No definition available. No authoritative reference available. false 8 Accounts receivable: 3 us-gaap_ReceivablesNetCurrentAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 9 Trade, net of allowance 4 xec_AccountsReceivableTradeNetCurrent xec false debit instant monetary Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is... false false false false false false false false false 1 false true 41252000 41252 false false 2 false true 73676000 73676 false false Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for trade receivables that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection. No authoritative reference available. false 10 Oil and gas sales, net of allowance 4 xec_AccountsReceivableOilAndGasSalesNetCurrent xec false debit instant monetary Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is... false false false false false false false false false 1 false true 176551000 176551 false false 2 false true 136606000 136606 false false Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for oil and gas sales receivables that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection. No authoritative reference available. false 11 Gas gathering, processing, and marketing, net of allowance 4 xec_AccountsReceivableGasGatheringProcessingAndMarketingNetCurrent xec false debit instant monetary Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is... false false false false false false false false false 1 false true 6292000 6292 false false 2 false true 6974000 6974 false false Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for gas gathering, processing and marketing receivables that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection. No authoritative reference available. false 12 Other 4 us-gaap_OtherReceivables us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 3801000 3801 false false 2 false true 41826000 41826 false false No definition available. No authoritative reference available. false 13 Oil and gas well equipment and supplies 3 xec_OilAndGasWellEquipmentAndSupplies xec false debit instant monetary Carrying amount (lower of cost or market) as of the balance sheet date of oil and gas well equipment and supplies less... false false false false false false false false false 1 false true 145153000 145153 false false 2 false true 186062000 186062 false false Carrying amount (lower of cost or market) as of the balance sheet date of oil and gas well equipment and supplies less valuation and other allowances. No authoritative reference available. false 14 Deferred income taxes 3 us-gaap_DeferredTaxAssetsNetCurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 15837000 15837 false false 2 false true 2435000 2435 false false No definition available. No authoritative reference available. false 15 Derivative instruments 3 us-gaap_DerivativeInstrumentsAndHedges us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 1238000 1238 false false 2 false false 0 0 false false No definition available. No authoritative reference available. false 16 Other current assets 3 us-gaap_OtherAssetsCurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 13997000 13997 false false 2 false true 63148000 63148 false false No definition available. No authoritative reference available. false 17 Total current assets 3 us-gaap_AssetsCurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 407258000 407258 false false 2 false true 514944000 514944 false false No definition available. No authoritative reference available. true 18 Oil and gas properties at cost, using the full cost method of accounting: 2 xec_OilAndGasPropertiesFullCostMethodNetAbstract xec false na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 19 Proved properties 3 xec_ProvedOilAndGasPropertiesFullCostMethodGross xec false debit instant monetary Depletable oil and gas properties under the full cost method. Includes oil and gas properties with proved reserves, dry hole... false false false false false false false false false 1 false true 7549861000 7549861 false false 2 false true 7052464000 7052464 false false Depletable oil and gas properties under the full cost method. Includes oil and gas properties with proved reserves, dry hole costs, abandoned costs and Asset Retirement.These are capitalized costs of properties that have been evaluated. No authoritative reference available. false 20 Unproved properties and properties under development, not being amortized 3 xec_UnprovedOilAndGasPropertiesAndPropertiesUnderDevelopmentNotBeingAmortizedFullCostMethod xec false debit instant monetary Oil and Gas properties with unproved reserves under the full cost method and that are not being amortized, including property... false false false false false false false false false 1 false true 399724000 399724 false false 2 false true 465638000 465638 false false Oil and Gas properties with unproved reserves under the full cost method and that are not being amortized, including property under development. No authoritative reference available. false 21 Total oil and gas properties at gross 3 xec_OilAndGasPropertiesFullCostMethodGross xec false debit instant monetary Oil and Gas properties, gross, carried under the full cost method. false false false false false false false false false 1 false true 7949585000 7949585 false false 2 false true 7518102000 7518102 false false Oil and Gas properties, gross, carried under the full cost method. No authoritative reference available. true 22 Less - accumulated depreciation, depletion and amortization 3 xec_OilAndGasPropertiesFullCostMethodAccumulatedDepreciationDepletionAndAmortization xec false credit instant monetary Accumulated depreciation, depletion, amortization and impairments of oil and gas properties carried under the full cost... false false false false false false false false false 1 false true -5764669000 -5764669 false false 2 false true -4709597000 -4709597 false false Accumulated depreciation, depletion, amortization and impairments of oil and gas properties carried under the full cost method. No authoritative reference available. false 23 Net oil and gas properties 3 xec_OilAndGasPropertiesFullCostMethodNet xec false debit instant monetary Oil and Gas properties net of accumulated depreciation, depletion and amortization, Impairment and abandonment, carried under... false false false false false false false false false 1 false true 2184916000 2184916 false false 2 false true 2808505000 2808505 false false Oil and Gas properties net of accumulated depreciation, depletion and amortization, Impairment and abandonment, carried under the full cost method. No authoritative reference available. true 24 Fixed assets, less accumulated depreciation of $88,544 and $67,020 2 us-gaap_PropertyPlantAndEquipmentNet us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 127237000 127237 false false 2 false true 119616000 119616 false false No definition available. No authoritative reference available. false 25 Goodwill 2 us-gaap_Goodwill us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 691432000 691432 false false 2 false true 691432000 691432 false false No definition available. No authoritative reference available. false 26 Other assets, net 2 us-gaap_OtherAssetsNoncurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 33694000 33694 false false 2 false true 30436000 30436 false false No definition available. No authoritative reference available. false 27 Total assets 2 us-gaap_Assets us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 3444537000 3444537 false false 2 false true 4164933000 4164933 false false No definition available. No authoritative reference available. true 30 Accounts payable: 3 us-gaap_AccountsPayableCurrentAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 31 Trade 4 us-gaap_AccountsPayableTradeCurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 18309000 18309 false false 2 false true 89221000 89221 false false No definition available. No authoritative reference available. false 32 Gas gathering, processing, and marketing 4 xec_AccountsPayableGasGatheringProcessingAndMarketing xec false credit instant monetary Carrying value as of the balance sheet date of obligations incurred and payable to third parties for gas gathering,... false false false false false false false false false 1 false true 11905000 11905 false false 2 false true 11936000 11936 false false Carrying value as of the balance sheet date of obligations incurred and payable to third parties for gas gathering, processing and marketing. No authoritative reference available. false 33 Accrued liabilities: 3 us-gaap_AccruedLiabilitiesCurrentAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 34 Exploration and development 4 xec_AccruedLiabilitiesExplorationAndDevelopment xec false credit instant monetary Carrying value as of the balance sheet date of obligations incurred and payable, pertaining to costs for the exploration and... false false false false false false false false false 1 false true 52781000 52781 false false 2 false true 111511000 111511 false false Carrying value as of the balance sheet date of obligations incurred and payable, pertaining to costs for the exploration and development of oil and gas properties. No authoritative reference available. false 35 Taxes other than income 4 xec_TaxOtherThanIncome xec false credit instant monetary All taxes other than income taxes, mainly production severance taxes and ad valorem taxes as of the balance sheet date. false false false false false false false false false 1 false true 27956000 27956 false false 2 false true 26473000 26473 false false All taxes other than income taxes, mainly production severance taxes and ad valorem taxes as of the balance sheet date. No authoritative reference available. false 36 Other 4 us-gaap_OtherAccruedLiabilitiesCurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 155078000 155078 false false 2 false true 126010000 126010 false false No definition available. No authoritative reference available. false 37 Derivative instruments 3 us-gaap_DerivativeInstrumentsAndHedgesLiabilities us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 13902000 13902 false false 2 false false 0 0 false false No definition available. No authoritative reference available. false 38 Revenue payable 3 xec_RevenuePayableCurrent xec false credit instant monetary Revenue payable for the working interest and royalty interests not distributed. Used to reflect the current portion of the... false false false false false false false false false 1 false true 108832000 108832 false false 2 false true 104438000 104438 false false Revenue payable for the working interest and royalty interests not distributed. Used to reflect the current portion of the liabilites. No authoritative reference available. false 39 Total current liabilities 3 us-gaap_LiabilitiesCurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 388763000 388763 false false 2 false true 469589000 469589 false false No definition available. No authoritative reference available. true 40 Long-term debt 2 us-gaap_LongTermDebtNoncurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 392793000 392793 false false 2 false true 587630000 587630 false false No definition available. No authoritative reference available. false 41 Deferred income taxes 2 us-gaap_DeferredTaxLiabilitiesNoncurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 348897000 348897 false false 2 false true 500945000 500945 false false No definition available. No authoritative reference available. false 42 Asset retirement obligation 2 us-gaap_AssetRetirementObligationsNoncurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 129785000 129785 false false 2 false true 125338000 125338 false false No definition available. No authoritative reference available. false 43 Other liabilities 2 us-gaap_OtherNoncurrentLiabilities us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 146193000 146193 false false 2 false true 129784000 129784 false false No definition available. No authoritative reference available. false 44 Total liabilities 2 us-gaap_Liabilities us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 1406431000 1406431 false false 2 false true 1813286000 1813286 false false No definition available. No authoritative reference available. true 46 Stockholders' equity: 2 us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 47 Preferred stock, $0.01 par value, 15,000,000 shares authorized, no shares issued 3 us-gaap_PreferredStockValue us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 0 0 false false 2 false true 0 0 false false No definition available. No authoritative reference available. false 48 Common stock, $0.01 par value, 200,000,000 shares authorized, 83,541,995 and 84,144,024 shares issued, respectively 3 us-gaap_CommonStockValue us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 835000 835 false false 2 false true 841000 841 false false No definition available. No authoritative reference available. false 49 Treasury stock, at cost, zero and 885,392 shares held, respectively 3 us-gaap_TreasuryStockValue us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false false 0 0 false false 2 false true -33344000 -33344 false false No definition available. No authoritative reference available. false 50 Paid-in capital 3 us-gaap_AdditionalPaidInCapital us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 1859255000 1859255 false false 2 false true 1874834000 1874834 false false No definition available. No authoritative reference available. false 51 Retained earnings 3 us-gaap_RetainedEarningsAccumulatedDeficit us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 178035000 178035 false false 2 false true 510271000 510271 false false No definition available. No authoritative reference available. false 52 Accumulated other comprehensive (loss) income 3 us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true -19000 -19 false false 2 false true -955000 -955 false false No definition available. No authoritative reference available. false 53 Total stockholders' equity 3 us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 2038106000 2038106 false false 2 false true 2351647000 2351647 false false No definition available. No authoritative reference available. true 54 Total liabilities and stockholders' equity 2 us-gaap_LiabilitiesAndStockholdersEquity us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 true true 3444537000 3444537 false false 2 true true 4164933000 4164933 false false No definition available. No authoritative reference available. true false 2 48 false Thousands UnKnown UnKnown false true